Herpesvirus ateles (H. ateles) is an indigenous virus of spider monkeys which is highly oncogenic in various subhuman primate species. The virus is able to transform monkey lymphocytes in vitro. The objective of this proposal is to investigate the structure, functional organization and expression of H. ateles DNA in virus-transformed cells. The basis of these studies shall be a structural analysis of the DNA isolated from purified H. ateles virions by restriction endonucleases and by partial denaturation mapping with the electron microscope. Purified repetitive DNA (H-DNA) and non-repetitive DNA (L-DNA) and restriction fragments of L-DNA shall be used for a quantitation of viral DNA in transformed lymphoblastoid cell lines by reassociation kinetics. Non-integrated circular viral DNA molecules shall be isolated from transformed cells and characterized by partial denaturation mapping. Temperature-sensitive mutants shall be created and temperature-dependence of viral gene expression in transformed cells shall be tested. Attempts will be made to transform lymphoid primate cells by intact or fragmented H. ateles DNA in vitro and after animal inoculation. A search for viral antigens in transformed cells shall be done by immunofluorescence methods using antisera from various monkey species.